The inventive concepts disclosed herein generally relate to analyzers for multiple-profile reagent cards, and more particularly, but not by way of limitation, to a waste ramp configured to stack used reagent cards during the operation of automated reagent card analyzers.
To satisfy the needs of the medical profession as well as other expanding technologies, such as the brewing industry, chemical manufacturing, etc., a myriad of analytical procedures, compositions, and tools have been developed, including the so-called “dip-and-read” type reagent test devices. Regardless of whether dip-and-read test devices are used for the analysis of a biological fluid or tissue, or for the analysis of a commercial or industrial fluid or substance, the general procedure involves a test device coming in contact with the sample or specimen to be tested, and manually or instrumentally analyzing the test device.
Dip-and-read reagent test devices can be manufactured at relatively low cost and are very convenient for individuals to use. Consequently dip-and-read reagent test devices enjoy wide use in many analytical applications, especially in the chemical analysis of biological fluids, because of their relatively low cost, ease of usability, and speed in obtaining results. In medicine, for example, numerous physiological functions can be monitored merely by dipping a dip-and-read reagent test device into a sample of body fluid or tissue, such as urine or blood, and observing a detectable response, such as a change in color or a change in the amount of light reflected from, or absorbed by the test device.
Many of the dip-and-read reagent test devices for detecting body fluid components are capable of making quantitative, or at least semi-quantitative, measurements. Thus, by measuring the detectable response after a predetermined time, a user can obtain not only a positive indication of the presence of a particular constituent in a test sample, but also an estimate of how much of the constituent is present. Such dip-and-read reagent test devices provide physicians and laboratory technicians with a facile diagnostic tool, as well as with the ability to gauge the extent of disease or of bodily malfunction.
Illustrative of dip-and-read reagent test devices currently in use are products available from Siemens Healthcare Diagnostics Inc. under the trademark MULTISTIX, and others. Immunochemical, diagnostic or serological test devices, such as these usually include one or more carrier matrix, such as absorbent paper, having incorporated therein a particular reagent or reactant system which manifests a detectable response (e.g., a color change) in the presence of a specific test sample component or constituent. Depending on the reactant system incorporated with a particular matrix, these test devices can detect the presence of glucose, ketone bodies, bilirubin, urobilinogen, occult blood, nitrite, and other substances. A specific change in the intensity of color observed within a specific time range after contacting the dip-and-read reagent test device with a sample is indicative of the presence of a particular constituent and/or its concentration in the sample. Some other examples of dip-and-read reagent test devices and their reagent systems may be found in U.S. Pat. Nos. 3,123,443; 3,212,855; and 3,814,668.
However, dip-and-read reagent test devices suffer from some limitations. For example, dip-and-read reagent test devices typically require a technician to manually dip the test device into a sample, wait for a prescribed amount of time, and visually compare the color of the test device to a color chart provided with the test device. This process is slow and the result reading is skill-dependent (e.g., exact timing, appropriate comparison to the color chart, ambient lighting conditions, and technician vision) and may be inconsistent between two different technicians performing the same test. Finally, the act of manually dipping the test device into the sample may introduce cross-contamination or improper deposition of the test sample on the test device, such as via incomplete insertion of the test device into the sample, insufficient time for the sample to be deposited onto the test device, or having too much sample on the test device which may drip, leak, or splash on the technician's work area, person, or clothing.
Testing tools and methods have been sought in the art for economically and rapidly conducting multiple tests, especially via using automated processing. Automated analyzer systems have an advantage with respect to cost per test, test handling volumes, and/or speed of obtaining test results or other information over manual testing. One such automated analyzer system is the CLINITEK ATLAS urinalysis system available from Siemens Healthcare Diagnostics.
Automated instruments which are currently available for instrumentally reading individual dip-and-read reagent test devices, or reagent strips, (e.g., CLINITEK STATUS reflectance photometer, manufactured and sold by Siemens Healthcare Diagnostics, Inc.) require each dip-and-read reagent test device to be manually loaded into the automated instrument after contacting the test device with specimen or sample to be tested. Manual loading requires that the reagent test device be properly positioned in the automated instrument within a limited period of time after contacting the solution or substance to be tested. At the end of the analysis, used test devices are removed from the instrument and disposed of in accordance with applicable laws and regulations.
Traditional dip-and-read test devices were designed with manual use in mind and are not particularly well suited for use with highly automated instruments, due to their small size and limited number of tests per each test device. A different test device format is presently used in the CLINITEK ATLAS automated urinalysis system, which is manufactured and sold by Siemens Healthcare Diagnostics. The CLINITEK ATLAS instrument uses a cassette containing reagent areas mounted seriatim on a continuous plastic substrate which is wound into a reel rotatably housed in the cassette. While the reagent cassette is well suited for automation, the manufacturing cost for this type of format amounts to eight times that of the dip-and-read reagent test device format described above.
Another recent development is the introduction of multiple-profile reagent cards and multiple-profile reagent card automated analyzers. Multiple-profile reagent cards are essentially card-shaped test devices which include multiple reagent-impregnated matrices or pads for simultaneously or sequentially performing multiple analyses of analytes, such as the one described in U.S. Pat. No. 4,526,753, for example. Multiple-profile reagent cards result in an efficient, economical, rapid, and convenient way of performing automated analyses. An automated analyzer configured to use multiple-profile reagent cards typically takes a multiple-profile reagent card, such as from a storage drawer, or a cassette, and advances the multiple-profile reagent card through the analyzer over a travelling surface via a card moving mechanism. The moving mechanism may be a conveyor belt, a ratchet mechanism, a sliding ramp, or a card-gripping or pulling mechanism, for example. As the multiple-profile reagent card is moved or travels along the travelling surface, one or more pipettes (e.g., manual or automatic) may deposit one or more samples or reagents onto one or more of the matrices or pads on the multiple-profile reagent card. Next, the multiple-profile reagent card may be analyzed (e.g., manually or automatically) to gauge the test result, such as via an optical imaging system, a microscope, or a spectrometer, for example. Finally, the used card is removed from the analyzer, and is disposed of in an appropriate manner.
However, as multiple-profile reagent cards are relatively rapidly moved through the automated analyzer, there is a need for an efficient method of collecting and disposing of used multiple-profile reagent cards. For example, used multiple profile reagents cards may contain harmful or hazardous chemical or biological agents, and may pose a risk of cross-contamination if handled or disposed of improperly. Further, the high-volume throughput of automatic analyzers may result in a large number of multiple-profile reagent cards that need to be removed from the automatic analyzer, which may cause downtime for the automatic analyzer, or an increased workload for technicians or other personnel, for example.